Tool for drilling a ledged hole

ABSTRACT

The tool has a cylindrical body with a shank adapted to fit in a drill and, adjacent its other end, has a rectangular slot therethrough from side to side at its center. In the slot, a rectangular blade is pivotally mounted at one end so as to be moveable from a position disposed diagonally and completely in the slot to a transverse position with the cutting end of the blade projecting from the slot. An axially extending push-rod has one end projecting from the body end and its other end adapted to push the blade to its projecting position. Axially aligned with the push-rod is a spring pressed plunger biasing the blade to its slot contained position. A hole is first drilled conventionally in a concrete or other ceiling, the tool is then inserted in the hole and rotated and, when the push-rod meets the closed end of the drilled hole, pushes the blade for grinding a ledged hole in which a toggle-type fastener may be engaged.

United States Patent 11 1 Giustino June 11, 1974 TOOL FOR DRILLING A LEDGED HOLE [76] Inventor: John Giustino, 2200 Hallandale ABSTRACT Blvd E Hallandale 33009 The tool has a cylindrical body with a shank adapted [22] Filed: Jan. 4, 1973 to fit in a drill and, adjacent its other end, has a rectangularvslot therethrough from side to side at its cen- [211 App! 32l005 ter. In the slot, a rectangular blade is pivotally mounted at one end so as to be moveable from a posi- [52] US. Cl. 175/289, 408/704 tion disposed diagonally and completely in the slot to [5 l Int. Cl E21b 9/26 a transverse position with the cutting end of the blade [58] Field of Search 175/284, 291; 408/704, projecting from the slot. An axially extending push- 408/199 rod has one end projecting from the body end and its other end adapted to push the blade to its projecting [56] References Cited position; Axially aligned with the push-rod is a spring UNITED STATES PATENTS pressed plunger biasing the blade to its slot contained 530 510 12/1894 Elliot et al. 175 291 position A hole is first drilled c9nvemiqnany in a 560I787 5/l896 EIliott..........: 175/284 Crete or other ceiling the tool melted in the 1,070,750 8/I9l3 Thumm 175/289 hole and rotated and, When the P meets the 2,756,968 7/l956 Emanuel et al 175/289 closed end of the drilled hole, Pushes the blade for 2,872,160 2/1959 Bang 175/289 grinding a ledged hole in which a toggle-type fastener Primary ExaminerJames Av Leppink may be engaged.

1 Claim, 5 Drawing Figures TOOL FOR DRILLING A LEDGED HOLE BACKGROUND OF THE INVENTION This invention relates to a drill type tool which has a blade pivotally mounted in a recess in the tool and moveable from a position totally contained in the recess to a position in which one end of the blade protrudes from the recess for grinding a ledge with which a toggle-type fastener may be engaged. Means are provided for extending the blade while the tool is rotated in a predrilled hole.

Prior art tools are known for forming transverse recesses which are irregular in a direction parallel to the axis of the rotating tool. Many such tools are known which have recess forming means operated by movement of one or more parts axially of the tool while it is being rotated, but all such known devices are complicated and expensive to make and are difficult to use.

The primary object of this invention is to provide such a tool which is inexpensively manufactured and easy to use for forming a ledged hole in concrete ceilings in which toggle-type fasteners may be engaged for hanging therefrom lighting or other fixtures.

SUMMARY OF THE INVENTION This invention contemplates a drill-type tool having a rectangular recess therethrough near the end of the tool remote from the end gripped by a drill. A blade is pivotally mounted in this recess so as to be moveable from a position diagonally disposed and completely in the recess to a position projecting radially of the tool for grinding a ledge. A push-rod is provided projecting axially of the remote end of the tool for moving the blade to its projecting position when the tool is rotated in a hole predrilled partially through a concrete ceiling.

BRIEF DESCRIPTION OF TI-IEDRAWINGS FIG. 1 is a fragmentary, longitudinal sectional view of a tool embodying the invention, shown with the blade projecting from the tool;

FIG. 2 is a fragmentary, side elevational view thereof, shown with the blade completely contained in the recess, the interior parts being indicated in phantom lines;

FIGS. 3 and 4 are plan and bottom plan views, respectively, of the tool of FIG. 2; and

FIG. 5 is a fragmentary, longitudinal sectional view of a ceiling having a hole therein shaped by the tool of FIG. 2, together with a toggle-type fastener secured therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the figures of the drawing, the tool has a shank end 11 adapted to be received in the chuck Oscillatably mounted in slot 14 is a rectangular blade 15 which has one end pivotally secured by a pin 16 therethrough and through an appropriate hole through the tool, as shown in FIG. 3. The pin is located near one side of slot 14, as seen in FIG. 1, and blade 15 may be swung upward in the slot so that it is entirely contained in the slot, as shown in FIG. 2, the swung end being bevelled, as shown, for this purpose.

As seen in FIG. ll, blade 15 is limited in its outward movement to a horizontal disposition by the floor of the slot 14, the end of the blade projecting out from the slot.

Axially aligned with the hole containing push-rod 13, is another hole containing a plunger 17 biased upward by a spring 18 and engaging the blade 15 at one side of the pin 16 for normally biasing the blade to its withdrawn position.

Referring now to FIG. 5, a hole 19 is drilled by conventional drill means partially through a concrete ceiling indicated fragmentarily at 20.

The tool 10 is then operated as follows: the shank 11 is engaged in the chuck of a drill and the tool is inserted in the hole 19 until the outer end of push-rod 13 engages the top of the hole. The tool 10 is then rotated and as it is pushed up toward the end of the hole it forces the blade 15 to swing down and out, as the blade grinds, from the position shown in FIG. 2 to that shown in FIG. 1, forming an annular recess 21 in the hole 19, as seen in FIG. 5.

A toggle-type fastener such as that shown in FIG. 5 may then be engaged in the recess 21 for supporting a lighting fixture or the like.

I claim:

1. A tool for forming an annular ledge in a hole predrilled partially through a concrete ceiling, comprising: a cylindrical body extending from a shank end to a remote end, the body having a rectangular slot extending laterally therethrough adjacent the remote end, a rectangular blade mounted in the recess, a pin oscillatably securing the blade and extending through one end of the blade and through holes through the body on each side of the slot and adjacent one end of the slot, the other grinding end of the blade being biased for adapting the blade to be entirely contained within the slot when it is disposed diagonally in the slot, a push-rod disposed in an axially extending hole in the body, one end of the rod protruding from the remote end and the other end extending into the slot, the cylindrical body having a second hole axially aligned with the push-rod hole and extending from the slot in the direction of, and short of, the shank end; and a spring pressed plunger in the second hole for biasing the blade to its diagonally disposed position; whereby the blade is adapted to be pushed by the rod to a'laterally disposed position with its end protruding from the tool for grinding an annular ledge when the tool is rotated and the rod engages the end of the predrilled hole, and the blade is returned within the slot when the tool iswithdrawn from the hole. 

1. A tool for forming an annular ledge in a hole predrilled partially through a concrete ceiling, comprising: a cylindrical body extending from a shank end to a remote end, the body having a rectangular slot extending laterally therethrough adjacent the remote end, a rectangular blade mounted in the recess, a pin oscillatably securing the blade and extending through one end of the blade and through holes through the body on each side of the slot and adjacent one end of the slot, the other grinding end of the blade being biased for adapting the blade to be entirely contained within the slot when it is disposed diagonally in the slot, a push-rod disposed in an axially extending hole in the body, one end of the rod protruding from the remote end and the other end extending into the slot, the cylindrical body having a second hole axially aligned with the push-rod hole and extending from the slot in the direction of, and short of, the shank end; and a spring pressed plunger in the second hole for biasing the blade to its diagonally disposed position; whereby the blade is adapted to be pushed by the rod to a laterally disposed position with its end protruding from the tool for grinding an annular ledge when the tool is rotated and the rod engages the end of the predrilled hole, and the blade is returned within the slot when the tool is withdrawn from the hole. 